Method and apparatus for forming cast wall panels

ABSTRACT

A method and system for constructing wall panels made of a foam insulation wythe and a concrete structural wythe. The insulation wythe is made up of a foam plank having a body having opposing flanges and receiving mounting angles that provide attachment for interior building finish. The method of the invention includes the steps of placing a plurality of insulation wythes adjacent to each other on a horizontal surface within a mold such that the plank bodies point upwardly, pouring concrete over the sections, allowing the concrete to cure to form the structural wythe, then tilting the finished wall panel to a substantially vertical orientation. Optionally, the method of the present invention includes the steps of placing spacers between adjacent planks, placing mounting angles in the undersides of the primary wall sections and placing reinforcing means over the sections within the mold.

BACKGROUND

This application claims priority to U.S. Provisional App. No. 60/513,628 filed on, Oct. 23, 2003, the contents of which are hereby incorporated by reference.

The present invention relates to methods and apparatus for forming wall panels for buildings and, more particularly, to methods and apparatus for forming cast concrete wall panels for use in site cast (tilt-up) and/or manufactured plant cast (pre-cast) construction.

Tilt-up construction is a popular and economical construction technique. The procedure begins with the pouring of a foundation for the structure to be built. After the foundation is complete, a floor slab is poured. Frames or perimeters, preferably made of wood or metal and formed in the shapes and dimensions of the walls of the structure, are assembled on a horizontal surface, preferably at the construction site and preferably on the poured floor slab. Smaller frames or perimeters in the shapes of windows and doors are placed within the larger frames at the desired locations of the doors and windows. Reinforcing steel, in the form of mesh and/or bars, is placed within the larger frames and concrete is poured in the frames. Preferably, specialized hardware is also placed in the frames to facilitate the lifting of the finished panel by a crane or the like, to accept temporary wind braces, and to accept roof joists. After the concrete has cured, the frames are removed and the finished wall panel is tilted to a vertical orientation and secured to the foundation. Finished cast wall panels are then joined to a common roof structure to complete the outer enclosure of the building. It is also known to provide crushed stone, marble chips, other decorative aggregate and many other formed shapes or surface treatment on the bottom of the casting area within frames in order to provide a wall panel with a decorative outer surface.

While such tilt-up building construction techniques utilizing panels cast horizontally out of concrete are economical and popular for large buildings, for relatively smaller buildings (approximately 40,000 square feet of floor area or less and 25 feet tall or less), they are not as economical as more conventional building techniques. One reason for this is that walls for smaller buildings require less strength. If the cast concrete walls are left thick, they are relatively expensive. However, if they are made thinner they become structurally unstable. A second reason is that the bulk of small buildings require insulation, some space toward the interior of the wall to install mechanical service components such as electrical and plumbing lines, and a wall board finish on the inside. Installing any or all of these on a wall constructed of concrete is costly and time-consuming. Wood or metal studs or other raised members must be attached to the concrete. Insulation and electrical lines must be installed between the raised members. Both of these tasks usually must occur while the walls are in the vertical position, which can be slow because of the need to elevate the workers.

Accordingly, there is a need for a tilt-up construction method and apparatus that is economical for relatively smaller buildings and that can accommodate insulation and service lines, such as electrical and plumbing lines.

SUMMARY OF THE INVENTION

The present invention is a method and apparatus for forming a cast wall panel in a horizontal position for use in tilt-up construction that simultaneously provides the panels with insulation and provides a surface for attaching interior finish materials. The method of the invention may be employed to form cast wall panels either at a construction site where the panels will be used or at a factory or plant remote from the construction site.

The apparatus of the invention preferably includes a wall panel made up of a foam insulation layer or wythe and a structural wythe, preferably made of cast concrete. The insulation wythe is made up of a series of planks, each having a body and a pair of opposing flanges. The flanges preferably include surfaces on which a tongue or a groove is formed so that the planks may be placed side-by-side and engage each other along adjacent flanges with a seam that minimizes leakage of concrete from the structural wythe. The undersides of the planks preferably are substantially flat and include slots and surface grooves shaped to receive mounting angles and electrical and plumbing service.

The wall panel of the present invention also includes plank spacers positioned between adjacent planks to vary the spacing between adjacent plank bodies. The spacers also include lateral edges having either a tongue or a groove to form tight seams with the flanges of adjacent planks.

In another embodiment of the present invention, the planks of the insulation wythe include caps shaped to conform to the outer contour of the plank body. Consequently, the addition of one or more caps to the outer contour of a plank body increases the depth of the concrete rib of the structural wythe at that point. The planks, spacers and caps preferably are made of plastic foam, such as expanded polystyrene, or other material that is relatively inexpensive, is easily shaped and has insulating properties.

The structural wythe is preferably made up of concrete and includes a rib defined by and formed between two adjacent plank bodies. As stated above, the width of a rib may be varied by the use of spacers between adjacent planks. The structural wythe is formed to include a veneer that extends over the plank bodies between two ribs. As stated above, the depth of the rib may be varied by the presence or absence of plank caps, which would reduce or increase, respectively, the rib thickness. The thickness of the veneer preferably remains constant.

In the method of the present invention, a plurality of planks are placed within a horizontally oriented frame or perimeter formed in the shape of the finished panel such that they are contiguous, so that the flanges of adjacent sections engage each other, and positioned substantially parallel to each other. The planks are oriented such that the plank bodies extend upwardly, thereby forming troughs or valleys there between. Preferably, steel mesh is placed on top of the planks, reinforcing bars are placed between the bodies and concrete is poured over the assembly. After the concrete cures, the finished wall panel, consisting of the insulation wythe and the structural wythe, is removed from the frame and is tilted upwardly into place. The concrete ribs in the troughs between plank bodies forms load-bearing stems or pilasters of the finished panel. The undersides of the foam sections of the finished wall panels thus form the inner surface of the structure of which the panel forms a part and can receive wall boards and the like.

Preferably, the apparatus of the invention includes several mounting angles mounted in slits attached to the undersides of the planks so that the angle will be visible on the inner surface of the completed wall panel when it is tilted into place. Each angle includes an inner flange shaped to be inserted into the underside of a selected plank and an outer flange shaped to lie flat against the plank. The angles are made of thin-gauge steel, rigid plastic or other substantially rigid material.

Other objects and advantages of the present invention will be apparent from the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a foam plank of the wall panel of the present invention;

FIG. 2 is a perspective view of a mounting angle of the wall panel of the present invention;

FIG. 3 is a perspective view of a plank spacer of the present invention;

FIG. 4 is a perspective view of an insulation wythe incorporating the plank of FIG. 1 and the optional mounting angle of FIG. 2;

FIG. 5 is a somewhat schematic, perspective view of a completed wall panel made from the wall form of FIG. 4 and cured concrete, including an attached wall board;

FIG. 6 is a perspective view of an alternate embodiment of the invention in which the insulation wythe includes plank spacers of the type shown in FIG. 3 and the optional mounting angle of FIG. 2;

FIG. 7 is a somewhat schematic, perspective view of a completed wall panel including the insulation wythe of FIG. 6 and cured concrete;

FIG. 8 is a perspective view of a plank cap of the present invention;

FIG. 9 is a somewhat schematic, perspective view of a finished wall panel including the insulation wythe of FIG. 4, plank caps of FIG. 8 and a cured concrete structural wythe;

FIG. 10 is a perspective view of formwork surrounding the insulation wythe of FIG. 4 including reinforcing steel and a frame, shown broken away;

FIG. 11 is a perspective view of a single piece of foam material divided by cut lines into planks of FIG. 1 and spacers of FIG. 3;

FIG. 12 is a perspective view of a single piece of material divided by cut lines into caps of FIG. 8;

FIG. 13 is a front elevational view of an alternate embodiment of a foam plank of the present invention;

FIG. 14 is a detail of a wall panel of the present invention showing structure around an opening in a finished wall panel;

FIG. 15 is a detail of a wall panel of the present invention showing the top of a finished panel; and

FIG. 16 is a detail of a wall panel of the present invention showing the bottom of a finished panel.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, a plank 106 of the wall panel of the present invention includes a relatively thick, elongate body 108 and a pair of relatively thin opposing flanges 110, 112 extending along the sides of the body. The body 108 also includes a flat bottom face 114 in which surface channels 116, 118 are cut longitudinally and are shaped to receive mechanical building service, including mechanical, electrical and plumbing service, in the finished wall. The body 108 also includes slots 120, 122 cut into and extending longitudinally along the bottom face 114. The lateral edge 124 of flange 110 is substantially flat and includes a raised tongue 126 that extends along substantially the entire length of the plank 106. Similarly, the lateral edge 128 of plank flange 112 is also substantially flat and includes a groove 130 shaped to receive the tongue 126. Consequently, the shapes of the lateral edges 124, 128 of the flanges 110, 112 of plank 106 form a tongue-and-groove engagement between adjacent sections, as shown in FIG. 4, thereby serving to align adjacent foam planks 106A-C.

The upper surface 132 of the body 108 is flat and is the widest portion of the body. The body 108 tapers inwardly from the surface 132 and narrows as it extends to the flanges 110, 112, forming undercuts 134, 136.

As shown in FIG. 2, a mounting angle 100 of the modular framework of the invention preferably is L-shaped in cross section and consists of an outer flange 102 preferably of a constant width (face-down in FIG. 2), and an inner flange 104, also preferably of constant width, preferably formed at a right angle to the outer flange. Inner flange 104 is shaped to be inserted into a slot 120 of the plank 106 of FIG. 1 such that the outer flange 102 lies flat against the bottom face 114 (see FIG. 4). Optionally, inner flange 104 may terminate in a return hook, barb or other mechanism 105 that prevents inner flange 104 being removed from the slot 120, 122 in which it is inserted. The mounting angle 100 may be made of steel, rigid plastic, wood or other substantially rigid material and preferably is approximately 2 in. on each side. Preferably, the slots 120, 122 are shaped such that the mounting angle does not extend through the plank 106 in which it is mounted so that heat is not conducted through the plank of the modular framework. The slots 120, 122 are preferably vertically oriented to facilitate the attachment of wall board. The flanges 102, 104 of the mounting angle 100 may be cut to form cutouts to allow mechanical service to pass through the mounting angle when mounted on a plank 106 (see FIG. 4).

As shown in FIG. 3, the present invention includes a plank spacer 138. The spacer is generally flat and is the substantially the same thickness as plank flanges 110, 112. Spacer 138 has substantially parallel upper and lower surfaces 140, 142, respectively, and substantially flat, parallel opposing lateral edges 144, 146. Lateral edge 144 includes a longitudinally extending tongue 148 similar in shape to tongue 126 (see FIG. 1) and lateral edge 146 includes a longitudinally extending groove 149 similar in shape to groove 130. Consequently, spacers 138 can be inserted between and engage the flanges 110, 112 of adjacent primary sections 106 to increase the spacing between the bodies 108 of adjacent planks 106.

As shown in FIG. 4, a prepared wall form or insulation wythe, generally designated 150, may be assembled that includes only planks 106A, 106B, 106C and mounting angles 100A, 100B, 100C, 100D, 100E, 100F. The mounting angles 100A-F are inserted into the slots 120, 122 of the planks 106A-C and fixed to the sections with adhesive or by other means. The planks 106A-C are positioned in side-by-side relation to create a series of parallel bodies 108A, 108B, 108C and to create between each pair of bodies a valley or trough 152A, 152B to the formwork where the formwork is thinner.

As shown in FIG. 5, a completed wall panel, generally designated 154, includes the insulation wythe 150 covered by a structural wythe 156 of cured concrete for which the insulation wythe served as part of the form for the concrete structural wythe and is now attached. As discussed below in greater detail, the wall panel 154 preferably is formed by placing the insulation wythe 150 horizontally on the undersides 114 of the planks 106A-C on a poured floor slab or other substantially flat, horizontal surface (preferably physically close to the structure to which the panel 154 is to be a part) and concrete is poured over the back of the insulation wythe. Preferably, the insulation wythe 150 is placed within a mold 181 (see FIG. 10).

Once the concrete has cured, forming the structural wythe 156, the completed wall panel 154 may be tilted to a vertical configuration and moved into place. Mounting angles 100A-F may be attached to the insulation wythe 150 either before or after application of the concrete to form the structural wythe 156. Thus, an entire exterior building structure can be fabricated by casting, then connecting finished wall panels 154 to other members of the building structure. Once the wall panel 154 is set into the vertical position, the insulation wythe 150 remains in place and may serve as insulation. Surface channels 116, 118 may receive mechanical building service, such as electrical and plumbing conduits and the like. Wall board 157 may be attached to the finished wall panel 150 by attachment to the mounting angles 100A-F (whose inner flanges 104 are embedded in the planks 106A-C) by fasteners such as screws or rivets (not shown) or by a suitable adhesive or, if mounting angles are not used, by attachment directly to the insulation wythe 150 by a suitable adhesive.

The outer flanges 102 of the mounting angles 100A-F will lie against the wall panel 150 in a vertical orientation and are spaced to receive fasteners, such as screws and the like, for wall board 157 or the like. Workers may put electrical lines, plumbing conduit and other service equipment (not shown) in the channels 116, 118 of each panel 106A-C and, if desired, cut additional channels (not shown) in the formwork. Furthermore, electrical boxes (not shown) may be attached to the mounting angles 100A-F.

The thicker concrete portions or ribs 158, 160 of the structural wythe 156 formed by the troughs 152A, 152B, respectively, between the bodies 108A-C of the insulation wythe 150 comprise vertical structural ribs or pilasters and give the finished wall panel 154. The ribs or pilasters provide structural strength not only for the construction loads necessary to erect the finished panel assembly, but they may also be engineered to provide integral structural capacity to the building structure itself, but without requiring as much concrete as would a flat concrete wall. The bodies 108 in each of the planks 106A-C in the formwork form a veneer 162, 164, 166 component of the structural wythe 156, which reduces the total amount of concrete in the structural wythe 156.

As shown in FIG. 6, an insulation wythe of the present invention, generally designated 150′, uses both the planks 106A-C and the spacers 138A, 138B. The spacers 138A-B make the troughs 152A′, 152B′ between the bodies 108 of the insulation wythe 150′ wider. Although a single spacer 138 is placed between adjacent planks 106, it is within the scope of the invention to place a plurality of spacers between planks to create even wider troughs 152A′, B′. Regardless of the configuration, the planks 106A-C and spacers 138A-B employed will be joined by engagement of tongues 126, 148 and grooves 130, 149 of the respective components (see FIGS. 1 and 2). It is also within the scope of the invention to provide the spacers 138 with a longitudinal slot 168 shaped to receive the inner flange 104 of mounting angle 100 such that outer flange 102 thereof lies flat against the bottom face 142 (FIG. 2) of the spacer and receives screws or the like to support wall board (not shown).

As shown in FIG. 7, a prepared wall panel 154′, consisting of the insulation wythe 150′ of FIG. 6 and a structural wythe 156′, has concrete ribs 158′, 160′ that are made wider as a result of the use of spacers 138A, 138B. These wider ribs 158′, 160′ have higher load-bearing strength than narrower ribs, which makes them preferred for structures with higher load requirements. As mentioned previously, even more spacers 138 may be added between planks 106 to bring the width of the ribs 158′, 160′ to a desired dimension. In this way, the strength of a wall panel 150 and the amount of concrete used to form a structural wythe 156 may be optimized for a particular structure with a relatively small amount of additional foam material and simple labor required to insert the spacers between planks 106.

A plank cap 170 is shown in FIG. 8. Plank cap 170 has substantially flat, parallel upper and lower surfaces 172, 174, respectively, and opposing, downturned lateral edges 176, 178. The plank cap 170 preferably is made of the same material as the plank 106, such expanded foam, preferably polystyrene. The plank cap 170 is shaped to fit on the upper surface 132 of a plank 106 (see FIG. 1) to increase the effective height of the plank body 108.

As shown in FIG. 9, insulation wythe 150″ includes plank caps 170A, 170B, 170C placed on the upper surfaces 132 of bodies 108 of planks 106A-C that create deeper concrete ribs 158″, 160″ and a thicker final wall panel 154″. This is an alternative means of increasing the strength of the ribs, and thereby the strength of the final wall 154″. Plank caps 170A, 170B, 170C may be used to create ribs 158, 160 of a desired depth without having to fabricate special versions of the plank 106. Accordingly, planks 106 can be fabricated in modular sizes, such as in a 2 ft. width or a 4 ft. width, although it is within the scope of the invention to fabricate primary wall sections of any desired width.

The addition of spacers 138 and planks caps 170 to the planks 106 can create a wide combination of rib widths and depths to form wall panels 154 of a wide variety of structural strengths and construction costs. This allows the panels 154 described herein to produce walls that fulfill a wide range of structural and economic requirements with only three standard form components, namely, the plank 106, spacer 138 and plank cap 170.

As shown in FIG. 10, the insulation wythe 150′″ may be topped with conventional steel reinforcing, generally designated 180, and is placed within a mold or frame 181 that is shaped to contain the concrete that will be poured over the form to form the structural wythe 156 (see FIG. 7). Reinforcing 180 includes a plurality of rebar chairs 182 positioned in the troughs 152 that hold steel reinforcing bars 184 in position so that the bars may be embedded lengthwise in the final concrete ribs 158, 160 (see FIG. 9, for example). Other chairs 186 are placed on the top surfaces 132 of the plank bodies 108 to elevate and hold in place welded wire mesh 188 so that the mesh can be embedded in the veneer 162-166 (see FIG. 5, for example) of the concrete structural wythe 156 that covers the entire top face of the form 150′″. Thus, steel reinforcing 180 may be incorporated into the wall panels 154 of the present invention by conventional means to augment the strength of the wall panels.

As shown in FIG. 11, of the planks 106 of the present invention might be cut out of a larger piece of material 190 with little or no waste. The close fit of the planks 106 and spacers 138 allows the planks and spacers to be cut with minimal waste.

Likewise, as shown in FIG. 12, many pieces of the plank cap 170 of the present invention may be “nested” in a single larger piece of material 192 so that there is minimal waste when the plank caps are cut out from that larger piece of material. These techniques reduce waste and help keep the cost of the formwork low.

As shown in FIG. 13, an alternate design for an insulation wythe 150′″ includes foam planks 106′, each having a body 108′ with a pair of large through channels 200 and two pairs of small through channels 202, 204. Through channels 200, 202, 204 preferably extend the length of the plank 106′ and provide a plank that is lighter than the solid plank 106 of FIG. 1 and requires less material for a plank of a given size than the plank of FIG. 1. Furthermore, through channels 200, 202, 204 may receive mechanical service components, such as plumbing, electrical and HVAC components, within the associated insulation wythe 150′″. The plank 106′ also may have steel sections 205 formed therein to support wall board and the like.

Each plank 106′ includes one or more cutouts 116′ shaped to receive mechanical service. The body 108′ of each plank 106′ is fitted with a plank cap 170′ if it is desired to make thicker the concrete of the ribs (not shown) formed between the plank bodies 108′. If it is desired to make the ribs wider, spacers 149′ may be employed between the planks 106′.

As shown in FIG. 14, when a wall panel 154 is formed, it is often necessary to form openings therein for windows and doors. Accordingly, when the form 181 (see FIG. 10) is made, wood frames 206, sized to the desired opening, are made of wood and placed within the form in the desired location on the finished panel. The frame includes lag bolts 208 that protrude from the frame outwardly in to the area of the form that receives concrete. The insulation wythe 150 includes strips 210, preferably of foam, that extend from the plank 106 to the frame 206. When the structural wythe 156 is poured, a thick band 212 of concrete extends about the frame. The frame 206 is securely attached to the concrete band 212 by the lag bolts 208 and thus can support door or window frames.

As shown in FIG. 15, it is often desirable to form a wall panel 154 with a parapet 214 of concrete at the top of the wall panel. This is achieved by placing a foam strip 216 in the form 181 (see FIG. 10) above the upper end of the insulation planks 106. Removable rectangular forms 218 (only one of which is shown in FIG. 15), which may be constructed of foam, are also inserted in the form and form voids in the structural wythe 156 shaped to receive roof trusses and the like (not shown) when the finished wall panel 154 is tilted up into position. Embedded angle 219 is attached to the foam strip 216 and attaches to and supports the structural members of the roof. Blocking 220 having lag bolts 222 or the like is placed in the form adjacent to a perimeter 224 of the form to provide a surface to support and attach to other roof structure.

As shown in FIG. 16, the bottom of a wall panel 154 may include a strip of wood or foam 228 placed between the bottom end of plank 106 and the bottom perimeter of the form 181 (see FIG. 10). A foundation connector 230 is placed in the form so that it is positioned at the bottom of the structural wythe 156. A typical foundation connector is shown in U.S. Pat. No. 5,609,005, the disclosure of which is incorporated herein by reference.

The method of forming and erecting the wall panels of the present invention is as follows. First, a base is prepared by leveling the ground at the construction site or pouring a flat concrete slab. A frame or perimeter is formed in the shape of the desired wall panel, and frames for all openings desired in the panel are formed and placed in the perimeter. The frames for the openings include lag bolts so that they are secured to the structural wythe of the completed panel. Foam planks and, optionally, spacers are then installed in the perimeter, and foam strips are added around the wood frame openings and as desired across the top and bottom of the planks. Typically, the planks are spaced approximately 9 to 12 inches from the bottom of the perimeter and about 15 inches from the roofline. This creates a solid base at the bottom of the finished panel and a solid concrete beam across the top of the finished panel. Foam sheets or other material may be placed in the perimeter form above the solid concrete beam to support and form a concrete panel parapet. Preferably, the foam is cut slightly larger than required to prevent its being blown out of the form.

Another advantage of the present invention is that the mounting angle 100 (see FIG. 2) may be inserted into the slots 120, 122 (see FIG. 1) after the wall panel 154 has been formed and tilted upright into position. Alternately, the slots 120, 122 may also be cut into the planks 106 and spacers 138 after a wall panel 154 has been formed and tilted upright into position. In addition, the mounting angles 100 may be shaped to be inserted into the planks 106 and spacers 138 without first forming slots, such as by forcing the flanges 104 into the expanded foam of the sections with a mallet.

Plastic sheeting is then installed over the parapet or top and bottom of the foam to facilitate easy stripping of the foam. Joist and beam seats are then installed as shown in FIG. 15. These may be pockets or, for joists, individual plates or a continuous angle located at the ledge created by the change in concrete thickness at that location. The lower reinforcing mat is then installed on spaced chairs. Vertical reinforcing is located in the rib area between bodies of the planks. Horizontal reinforcing is placed on top of this level at the top and bottom of the panels and at the top and bottom of all openings. The upper reinforcing mat is then installed on appropriately spaced chairs. Individual bars and/or welded wire fabric can be used for this mat. Individual vertical bars are placed above the lower level vertical bars in the ribs. Foundation connectors are placed in the lower area of the frame and are attached to the frame.

Lifting inserts and then installed and tied to the reinforcing mats. Examples of such inserts are disclosed in U.S. Pat. Nos. 5,857,296 and 6,260,900, the disclosures of which are incorporated herein by reference. Similarly, coil inserts for temporary wind braces are installed, such as those disclosed in U.S. Pat. No. 4,083,156. Chamfer strips (not shown) may be installed around the top of the forms around the perimeter of openings and along the edges of the panels. If desired, formwork is suspended for any reveals from the perimeter formwork. Debris is blown out of the formwork with high pressure air.

Concrete is then poured into the formwork immediately after the removal of debris, vibrated and is allowed to cure. The now-finished wall panel is tilted up to a substantially vertical orientation and is moved into place at its final location on the building. At this time, wind braces are attached to secure the wall panel in place. The exterior finish is then attached and, once the associated building has become weather-tight, the mounting angles are inserted into the insulation wythe and drywall is fastened to the insulation wythe either by attachment to the mounting angles or, if mounting angles are not used, by attachment directly to the insulation wythe. Alternately, drywall can be attached directly to the insulation wythe by adhesives, or to the steel sections shown in FIG. 13.

The forms and method of constructing wall panels of the present invention may be used to create wall panels for almost any type of structure, particularly small (40,000 square feet of floor area or less) enclosures that need to be insulated and finished. 

1. A wall panel system comprising: an insulation wythe including a plurality of planks, each made of a relatively light material and having a body, a flange and a spacer positioned between said planks; and a structural wythe made of a cured, relatively dense material formed to adhere to said insulation wythe, whereby when oriented in a substantially vertically, said structural wythe supports said insulation wythe.
 2. The wall panel of claim 1 wherein said dense material includes concrete.
 3. The wall panel of claim 1 wherein said light material includes foam.
 4. The wall panel of claim 1 wherein said spacer is separable from a remainder of said wythe.
 5. The wall panel of claim 1 wherein said spacer engages and is separable from said flange.
 6. The wall panel of claim 1 wherein said spacer is approximately equal in thickness to a thickness of said flange.
 7. The wall panel of claim 1 wherein said flange includes a first locking element and said spacer includes a second locking element shaped to engage said first locking element.
 8. The wall panel of claim 1 wherein said flange includes a groove and said spacer includes a projecting tongue shaped to engage said groove.
 9. The wall panel of claim 1 wherein said insulation wythe includes a surface channel formed therein shaped to receive mechanical service components.
 10. The wall panel of claim 1 further comprising wall board attached to said insulation wythe.
 11. The wall panel of claim 10 wherein said wall board is attached to said insulation wythe by an adhesive.
 12. The wall panel of claim 10 further comprising a mounting angle attached to said insulation wythe for supporting said wall board.
 13. The wall panel of claim 12 wherein said wall board is attached to said mounting angle.
 14. The wall panel of claim 12 wherein said insulation wythe includes a slot shaped to receive said mounting angle.
 15. The wall panel of claim 1 further comprising a plank cap positioned between said body and said structural wythe; whereby said structural wythe is made deeper adjacent to said flanges.
 16. The wall panel of claim 1 further comprising a plurality of plank caps stacked on said body and positioned between said body and said structural wythe; whereby said structural wythe is made deeper adjacent to said flanges.
 17. The wall panel of claim 16 wherein said plank caps are shaped to nest within each other.
 18. The wall panel of claim 17 wherein said plank caps are shaped to conform to an adjacent surface of said insulation wythe.
 19. The wall panel of claim 16 wherein said plank caps are made of a relatively light, foam material.
 20. The wall panel of claim 16 wherein said plank caps extend along substantially an entire length of said body.
 21. A wall panel system comprising: an insulation wythe including a plurality of elongate planks, each made of a relatively light foam material and having a body, a pair of opposing, longitudinal flanges having a first locking element including one of a tongue and a groove, and a spacer engaging and detachable from said flanges and positioned between said planks, said spacer being approximately equal in thickness to a thickness of said flanges and including a second locking element including one of a tongue and a groove and shaped to engage said first locking element; said insulation wythe includes a surface channel formed therein shaped to receive mechanical service components; and a structural wythe made of cured concrete formed to adhere to said insulation wythe, whereby when oriented in a substantially vertically, said structural wythe supports said insulation wythe.
 22. The wall panel of claim 21 further comprising wall board attached to said insulation wythe.
 23. The wall panel of claim 22 wherein said wall board is attached to said insulation wythe by an adhesive.
 24. The wall panel of claim 22 further comprising a mounting angle attached to said insulation wythe for supporting said wall board.
 25. The wall panel of claim 22 wherein said wall board is attached to said mounting angle.
 26. The wall panel of claim 22 wherein said insulation wythe includes a slot shaped to receive said mounting angle.
 27. A wall panel system comprising: an insulation wythe including a plurality of planks, each made of a relatively light material and having a body, a flange and a spacer positioned between said planks; a structural wythe made of a hardened, relatively dense material formed to adhere to said insulation wythe, whereby when oriented in a substantially vertically, said structural wythe supports said insulation wythe; and a plank cap made of a relatively light, foam material and positioned between said body and said structural wythe, said plank caps being shaped to conform to an adjacent surface of said insulation wythe; whereby said structural wythe is made thicker adjacent to said flanges and spacers.
 28. The wall panel of claim 27 wherein said plank caps are shaped to nest within each other.
 29. The wall panel of claim 28 wherein said plank caps extend along substantially an entire length of said body.
 30. A method for forming a wall panel comprising the steps of: forming an exterior perimeter approximating exterior dimensions of said wall panel; placing an insulation wythe including a plank made of a relatively light material and having a body, a flange and a spacer positioned adjacent to said plank, within said perimeter; pouring a hardenable material over said insulation wythe and curing said hardenable material to form a wall panel having a structural wythe attached to said insulation wythe; and removing said perimeter from said insulation and structural wythes to form a finished wall panel.
 31. The method of claim 30 further comprising the step of, subsequent to said removing step, tilting said wall panel to a substantially vertical orientation at an approximate final location of said wall panel in an associated structure.
 32. The method of claim 30 further comprising the step of installing reinforcing adjacent to said insulation wythe such that said reinforcing becomes embedded in said hardenable material.
 33. The method of claim 30 wherein said perimeter forming step includes the step of forming a perimeter of an opening in said wall panel within said exterior perimeter.
 34. The method of claim 33 wherein said step of forming a perimeter of an opening includes the step of shaping said planks to extend about said opening perimeter.
 35. The method of claim 34 wherein said step of forming a perimeter opening includes the step of attaching bolts to said perimeter opening such that said bolts extend outwardly from said perimeter opening.
 36. A method for forming a wall panel comprising the steps of: forming an exterior perimeter approximating exterior dimensions of said wall panel; placing an insulation wythe including a plank made of a relatively light material and having a body and a flange, within said perimeter; placing a cap made of a relatively light material over said plank; pouring a hardenable material over said insulation wythe and curing said hardenable material to form a wall panel having a structural wythe attached to said insulation wythe, whereby an effective thickness of said plank is increased at a location of said cap and a thickness of said hardenable material is increased adjacent to said location relative to thickness of said hardenable material without said cap at said location; and removing said perimeter from said insulation and structural wythes.
 37. The method of claim 36 further comprising the step of spacing said insulation wythe from a bottom of said exterior perimeter, whereby a solid base of said hardenable material is formed across a depth of said finished wall panel.
 38. The method of claim 37 wherein said spacing step includes the step of placing a filler element between said insulation wythe and said bottom of said exterior perimeter, thereby securing said insulation wythe within said exterior perimeter.
 39. The method of claim 38 further comprising the step of spacing said insulation wythe from a top of said exterior perimeter, whereby a solid beam is formed across a depth of said finished wall panel.
 40. The method of claim 39 wherein said spacing step includes the step of placing a filler element between said insulation wythe and said top of said exterior perimeter, thereby securing said insulation wythe within said exterior perimeter.
 41. The method of claim 36 further comprising the step of attaching mounting angle to said insulation wythe.
 42. The method of claim 41 further comprising the step of attaching interior building finish to said mounting angle.
 43. The method of claim 36 further comprising the step of forming surface channels in said insulation wythe for receiving mechanical service components therein.
 44. The method of claim 43 further comprising the step of placing mechanical service components in said surface channels of said finished wall panel.
 45. A method for forming a wall panel comprising the steps of: forming an exterior perimeter approximating exterior dimensions of said wall panel and forming a perimeter of an opening in said wall panel within said exterior perimeter; attaching bolts to said perimeter opening such that said bolts extend outwardly from said perimeter opening; placing an insulation wythe including a plurality of planks made of a relatively light material and having a body, a flange and a spacer positioned adjacent to and in between said planks, within said perimeter, and shaping said planks to extend about said opening perimeter; installing reinforcing adjacent to said insulation wythe; pouring a hardenable material over said insulation wythe and curing said hardenable material to form a wall panel having a structural wythe attached to said insulation wythe; and removing said perimeter from said insulation and structural wythes to form a finished wall panel; and subsequent to said removing step, tilting said wall panel to a substantially vertical orientation at an approximate final location of said wall panel in an associated structure.
 46. A wall panel system comprising: an insulation wythe including a plurality of planks, each made of a relatively light material and having a body and a flange; a mounting angle attached to said insulation wythe for supporting interior building finish; and a structural wythe made of a cured, relatively dense material formed to adhere to said insulation wythe, whereby when oriented in a substantially vertically, said structural wythe supports said insulation wythe.
 47. The wall panel of claim 46 wherein said insulation wythe includes a slot for receiving said mounting angle.
 48. The wall panel of claim 47 wherein said mounting angle includes a first flange shaped to be inserted into said slot.
 49. The wall panel of claim 48 wherein said mounting angle includes a second flange shaped to lie against said interior building finish. 